High-frequency semiconductor devices such as field-effect transistor elements using compound semiconductors like GaAs and GaN are rapidly being generalized and there is a strong demand for cost reduction. In order to respond to this demand, instead of totally sealed metal packages which have been used so far, low-priced mold packages are being adopted. However, when adopting non-sealed packages like mold packages, it is necessary to secure moisture resistance of semiconductor devices in order to prevent various kinds of deterioration attributable to moisture. For this reason, there is a demand for manufacturing semiconductor devices having a hollow hermetic sealing structure in which only necessary parts are sealed.
In conventional semiconductor devices, an insulating lid is bonded to a ceramic substrate on which a semiconductor element is mounted using glass to seal the semiconductor element (e.g., see Patent Literature 1). In this device, a dielectric constant of glass is 15 or below, a dielectric constant of the insulating lid is 15 or below and a difference in thermal expansion among the ceramic substrate, glass and lid is 1.2×10−6/° C. or below.